[VOL-1997] Remove transaction timeout for a non-active rw_core

This commit cleans up the transaction processing between two
cores in a pair.  It prevents the core not processing the request
to grab the request based on a timeout only.

Since this update heavily relies on the etcd mechanism then customized
local tests (not unit as could not find a full-featured etcd mock)
were run against it as well as some basic manual tests with
kind-voltha.

There is a TODO item in this commit to implement a peer-probe
mechanism to guarantee that a core in a pair has actually died
before a switch over is done.

Minor updates after first review.
Comments updates after second review

Change-Id: Ifc1442471595a979b39251535b8ee9210e1a52df
diff --git a/rw_core/main.go b/rw_core/main.go
index 2311029..e74d1bb 100644
--- a/rw_core/main.go
+++ b/rw_core/main.go
@@ -131,9 +131,7 @@
 		if err = c.SetTransactionContext(instanceId,
 			txnPrefix,
 			rw.kvClient,
-			rw.config.KVStoreTimeout,
-			rw.config.KVTxnKeyDelTime,
-			1); err != nil {
+			rw.config.KVStoreTimeout); err != nil {
 			log.Fatal("creating-transaction-context-failed")
 		}
 	}